Abstract:Objective To observe the dose-effect relation of fentanyl on postoperative hyperalgesia in patients undergoing laparoscopic cholecystectomy. Methods A total of 100 male patients aged 29 to 42 years old with American Society of Anesthesiologists (ASA) class Ⅰ or Ⅱ receiving scheduled laparoscopic cholecystectomy were selected and randomly divided into four groups (n=25, each):parecoxib sodium group (group P)and groups of different doses of fentanyl(groups F1, F2, F3). The intravenous anesthesia of propofol combined with fentanyl was used during operation in all patients. For postoperative analgesia, intravenous injection of 40 mg parecoxib sodium was given in group P, and intravenous injection of different doses of fentanyl was respectively given with a microinjection pump in groups F1 (0. 25 μg·kg^-1·h^-1), F2 (0.5 μg·kg^-1·h^-1) and F3 (1. 0 μg·kg^-1·h^-1) for hours at 5-min after tracheal catheter was drawn out. The visual analogue scale (VAS) pain score and Ramsay sedation score were evaluated at 10-min, 2, 4, 8, 12, 24 and 48 h after tracheal catheter was drawn out. The area of allodynia around surgical incision was measured. Nausea and vomiting, dizziness, excessive sedation and respiratory depression were recorded during observation period. Results There were no significant differences in VAS score and area of allodynia between groups F1, F2 and group P(all P>0.05). Compared with group P, the VAS score was higher, the area of allodynia was greater at postoperative 12 h to 48 h, and the incidence of dizziness was significantly higher at postoperative 48 h in group F3 (all P<0.05). Conclusion In laparoscopic cholecystectomy, fentanyl may cause opioid-induced hyperalgesia (OIH) with dose dependent.